On Fri, Jul 14, 2023 at 01:35:55PM -0700, Vinicius Costa Gomes wrote: > Bjorn Helgaas <helgaas@xxxxxxxxxx> writes: > > On Fri, Jul 14, 2023 at 01:05:41PM +0800, Kai-Heng Feng wrote: > >> When a system that connects to a Thunderbolt dock equipped with I225, > >> like HP Thunderbolt Dock G4, I225 stops working after S3 resume: > >> ... > > > >> The issue is that the PTM requests are sending before driver resumes the > >> device. Since the issue can also be observed on Windows, it's quite > >> likely a firmware/hardware limitation. > > > > Does this mean we didn't disable PTM correctly on suspend? Or is the > > device defective and sending PTM requests even though PTM is disabled? > > The way I understand the hardware bug, the device is defective, as you > said, the device sends PTM messages when "busmastering" is disabled. Bus Master Enable controls the ability of a Function to issue Memory and I/O Read/Write Requests (PCIe r6.0, sec 7.5.1.1.3). PTM uses Messages, and I don't think they should be affected by Bus Master Enable. I also don't understand the I225 connection. We have these Uncorrected Non-Fatal errors: > >> [ 606.527931] pcieport 0000:00:1d.0: AER: Multiple Uncorrected (Non-Fatal) error received: 0000:00:1d.0 > >> [ 606.528064] pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) > >> [ 606.528068] pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000 > >> [ 606.528072] pcieport 0000:00:1d.0: [20] UnsupReq (First) > >> [ 606.528075] pcieport 0000:00:1d.0: AER: TLP Header: 34000000 0a000052 00000000 00000000 > >> [ 606.528079] pcieport 0000:00:1d.0: AER: Error of this Agent is reported first > >> [ 606.528098] pcieport 0000:04:01.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID) > >> [ 606.528101] pcieport 0000:04:01.0: device [8086:1136] error status/mask=00300000/00000000 > >> [ 606.528105] pcieport 0000:04:01.0: [20] UnsupReq (First) > >> [ 606.528107] pcieport 0000:04:01.0: [21] ACSViol > >> [ 606.528110] pcieport 0000:04:01.0: AER: TLP Header: 34000000 04000052 00000000 00000000 They are clearly Unsupported Request errors caused by PTM Requests (decoding at https://bugzilla.kernel.org/show_bug.cgi?id=216850#c9), but they were logged by 00:1d.0 and 04:01.0. The hierarchy is this: 00:1d.0 Root Port to [bus 03-6c] 03:00.0 Switch Upstream Port to [bus 04-6c] 04:01.0 Switch Downstream Port to [bus 06-38] 06:00.0 Switch Upstream Port to [bus 07-38] 07:04.0 Switch Downstream Port to [bus 38] 38:00.0 igc I225 NIC If I225 sent a PTM request when it shouldn't have, i.e., when 07:04.0 didn't have PTM enabled, the error would have been logged by 07:04.0. The fact that the errors were logged by 00:1d.0 and 04:01.0 means that they were caused by PTM requests from 03:00.0 and 06:00.0. Bjorn
